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924RACR · Posted: Tue Jul 19, 2005 1:30 am Post subject: Stock '82 931 (US) dyno results

While at 944Fest this weekend, I took advantage of the free dyno time to have my car dynoed. It's bone stock, somewhere north of 150kmi, with a freshly home-rebuilt (500mi) turbo.

Results were a very consistent 122rwhp and 133 ft-lbs of torque (over two runs). Ambient conditions were maybe 75 deg F and very humid.

Sounded awesome on boost. I'll try to get the chart scanned in one of these days and post it. A/F readings were homing in on 12:1 up above 4000rpm. Torque hit about 120 right about 3000rpm, and stayed up there till 5000rpm, just like it says in the book. Peak HP at 5500.
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

endwrench · Joined: 07 Dec 2002 Posts: 1631 Location: Victor, Montana

Wow! Cool info! Thanks.

Now we can better estimate drivetrain losses on our own cars so better estimates of crank HP can be made.

Todd

924RACR · Posted: Tue Jul 19, 2005 3:07 am Post subject:

Well, 18% does put it down from 150hp (quoted stock crank output) to 123hp - pretty darn close to what I was clocked at. Given weather variation, that's good enough for me.
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Tigger937 · Posted: Tue Aug 23, 2005 4:26 pm Post subject:

Had my '81 dynoed in Feb. '03 and results were very similar...............

3rd Gear
Max. Power
123.2 RWHP @ 6000 RPM

Max. Torque
131.8 ft lbs @ 4250 RPM

2nd Gear
Max. Power
115.4 RWHP @ 5500 RPM

Max. Torque
113.8 ft lbs @ 5000 RPM

Modifications:
Stage 2 CAM
Duration 268
Lift 498
Overlap 48°
Only mod
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1981 931 (Concours)
1982 931 (Daily Driver)

"Think outside the box"

Raceboy · Joined: 01 Mar 2004 Posts: 2327 Location: Estonia, Europe

On turbo engine, overlap is evil. Better would be cam with stock duration and higher lift

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'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold

'84 924, turbocharged, sold.
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Tigger937 · Posted: Fri Aug 26, 2005 6:57 pm Post subject:

Wouldn't that rather depend on the application?
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1981 931 (Concours)
1982 931 (Daily Driver)

"Think outside the box"